To improve productivity, manufacturing companies have recently begun restructuring work to produce more goods with fewer assembly-line workers, and the companies have laid off many workers as a consequence. The workers laid off have been those with the least seniority(time on the job), generally the younger workers.

The statements above, if true, most strongly support which of the following as a conclusion？

(A) The products manufactured by the companies are not undergoing design changes while the manufacturing jobs are being restructured. (B) When assembly-line workers have made sug- gestions for improvements in manufacturing processes, some suggestions have been implemented, but many have not. (C) Assembly-line workers now need increased reading and mathematical skills to do their jobs. (D) Some of the innovations in assembly-line processes and procedures that were made to increase productivity have instead proved to be counterproductive. (E) The manufacturing companies are increasing the average age of their assembly-line workforce while still seeking to increase production.
_________________

D cannot be the answer because we do know about "increasing productivity". D talks about a theory via which the innovation in product line was counterproductive. Difficult to prove from the stem. We do not have such information.

We only know that the younger are laid-off. Actually, because they have less expertise.